Ambush Killings of the Police, 1970–2018: A Longitudinal Examination of the “War on Cops” Debate

Over the last few years, there has been a series of high-profile, premeditated ambush attacks on police, which has led some to conclude there is a “war on cops.” Unfortunately, prior research has not examined the prevalence of police ambushes over an extended period of time, and the most recent study only analyzed the phenomenon through 2013. Moreover, the “war on cops” thesis implies a very specific motivation for an ambush: hatred of police or desire to seek vengeance in response to police killings of citizens. Prior research has not sufficiently explored the motivations of ambush attacks, or whether recent trends in ambushes are linked to a “war on cops” motive. I investigate ambush killings of police from 1970 to 2018 using data from the Officer Down Memorial Page in an attempt to address these research gaps. I apply a temporal coding scheme of when the attack occurred to isolate killings of police that are consistent with the International Association of Chiefs of Police definition of an ambush. Results from linear regression show that the annual rates of ambush killings of police have declined by more than 90% since 1970. Although ambushes spiked in 2016 and 2018 to the highest rates in 20 years, interrupted time series analysis indicates no statistically significant increase post-2013. Spikes have also occurred in nonambush killings since 2014. Police leaders and researchers should monitor trends in ambush and nonambush killings of police, as the recent spikes may presage the emergence of a chronic problem.